docs: def save_freesurfer_geometry(filename, obj, volume_info=None, create_stamp=None):
      '''
      save_mgh(filename, obj) saves the given object to the given filename in the mgh format and
        returns the filename.
  
      All options that can be given to the to_mgh function can also be passed to this function; they
      are used to modify the object prior to exporting it.
      '''
      obj = geo.to_mesh(obj)
      fsio.write_geometry(filename, obj.coordinates.T, obj.tess.faces.T,
                          volume_info=volume_info, create_stamp=create_stamp)
      return filename